St. Tammany farmer. [volume] (Covington, La.) 1874-current, 1887-04-30
w. G.. kENTZEL, Editor.

then very much fainter than when dis
covered. il vas still fair first-magni
tude star. being as bright as Aide
baran. the most brilliant luminary il
the constellation of the Bull During
the next twelve months it gradually
faded. till at length it became quite in.
visible. No star can now be seen in
the position referred to IS occupied by
it; but some years ago. a minute sta,
was discovered near its place, and
where one was not hitherto known
From the fact that stars Of simi.
lar character to that of 1872 are
reported to have appeared in an
approximate position in the years 945
and 1864. some astronomers would have
us believe that q variable star having a
period OF somewhat over three hundred
years exists in this part Of the heavens.
II SO. we may not have long to wait for
another apparition of this most remark
able object. 1t should. however. be
borne in mind that if the star appeared
as suddenly As Tycho would lead us to
believe. there is great improbability
that it is periodically variable.
Thirty years after the disappearance
OF this object, another star blazed out
in the constellation Of Serpentarius and
remained visible for about three
months. It is said to have rivaled
Tycho's star in splendor; but as it was
not favorably situated for observation.
we have q very mcager array Of facts
concerning it. 1t is known as Keplcr's
star. having been described to us by
that astronomer.
Passing over the apparition Of one or
two stars too unimportant to be noticed,
we come now to the temporary stars Of
modern times. Here we have q great
advantage over the old astronomers,
for they, in dealing with temporary
stars. could record only their brilliancy.
duration of visibility, and facts Of q
similar kind; but since their time we
have had placed in our hands the telc-
scope and the spectroscope. the former
enabling us to watch star long after
it becomes invisible to the naked eve;
the latter giving us valuable information
on the changes in progress in its physical
constitution. Both of these instruments
have been employed with success in
observing the temporary stars of recent
times. and especially is this the case, as
regards the spectroscope at least, in
the observation of the star which ap-
peared in 1866 in the constellation Of
the Northern Crown, and which is
technically known rs the Blaze Star.
The Blaze Star was not, strictly speak
ing, > new one, as it was already
known to astronomers. The younger
Herschel in 1912 gave it as Of the sixth
magnitude; and Argelander in 1855
noted it as about the tenth-the object
in both cases being invisible to the
naked eye. We have therefore good
reason to believe that it was originally
variable. However, in 1866 ii suddenly
increased in splcndor, and when first
noticed. on the 18th Of May of that
year, was Of the second magnitude 1t
retained its splendor only n very short
time, for on the 24th Of the same month
it was invisible to the naked eve. In
August it again revived slightly; but
since that time it has been irregularly
decreasing.
During all these fluctuations it was
carefully examined both with the tele-
scope and the spcctroscope, but espe-
cially with the latter. What then
did the spectroscope reveal regarding
it, It revealed beyond Il doubt that
the sudden increase in brilliancy was
caused by an intense glowing Of the
hydrogen gas existing in the vaporous
envelope surrounding the star. All
stars are surrounded by an envelope
consisting of the vapors Of the materials
though not necessarily of all the ma
terials-of which the stars themselves
are composed. These vapors, though
intensely hot, are cool when compared
with the intenser heat of the star itself;
they therefore absorb more light and
heat than they emit, and when the
light Of a star is examined with
spectroscopc, this absorption
makes itself known in the long. mar
row. rainbow-colored band known as
the spectrum. BY the presence Of delicate
dark lines or gaps which are perpen-
dicular to the length Of the spectrum.
and which indicate that q certain definite
part Of the light is absent. Each vapor
has in any given spectrum its own
characteristic dark lines. But the
hydrogen lines in the spectrum Of the
Blaze Star. instead Of being dark. were
bright. In fact the whole extra light
Of the star seemed concentrated in four
bright lines, which were referred to the
elements nitrogen and hydrogen. The
brightness of these lines indicated that,
from some unknown cause. the hydrogen
gas existing in the vaporous envelope
of the Blaze Star had become 50 in
tensely heated that it burst out in .
sudden excess Of light which, to us,
converted the star from . faint to .
conspicuous object
OF the actual change we can form no
conception. Even Of the ordinary
changes in progress in the vaporous
envelope ofour own sun we have but
the faintest idea. Hydrogen gas forms,
we know. the chief constituent Of those
glowing vaporous masses known rs the
solar prominences. These prominences
are shot up from the surface Of the sun